Abstract: Objective To compare the prognosis of esopageal carcinoma treated with 3-dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiation therapy (IMRT) for patients older than 65 years;and to analysis the related factors affected the prognosis. Methods From January 2001 to December 2008, 105 cases of elderly patients with esopageal carcinoma were treated with 3D-CRT and 48 cases with IMRT. Local control rates, survival rates and its related prognostic factors were evaluated retrospectively with SSPS11.5 software. Results After the treatment with 3D-CRT or IMRT, there was 71 cases in CR, 78 in PR, and 4 in NR. The total efficiency (CR+PR) was 97.4%. The 1 and 3-year over-all survival rate was 70.6% and 34.2%, respectively; and the 1- and 3-year local control rate was 76.2% and 51.1%, respectively. Compared with the clinical data between 3D-CRT and IMRT, there were more patients with metastasis of lymph node, located in middle and lower-thoracic carcinoma, larger diameter of tumor in CT, higher dose of radiotherapy agents, and more patients was combination of chemotherapy in IMRT group (P<0.05). There were no significant differences in the effects of gender, age, T stage and diet before radiotherapy and lesion length bariesophagogram between the two groups (P>0.05). There were no significant differences in the 1- and 3-year survival rate and free-recurrence rate between 3D-CRT and IMRT groups(P>0.05). For all patients, analyzed by univariate analysis, the related factors affected on the prognosis were the different diet, site of lesion, T stage, metastasis of lymph node, lesion length in barium esophagogram and CT image, chemotherapy and the immediate response (P＜0.05). By Cox multivariate analysis, the independent factors affected on the prognosis were chemotherapy and the largest diameter of lesion in CT scanning image (P＜0.05). Conclusion s3D-CRT and IMRT can be considered as effective and feasible approaches for elderly patients with esophageal cancer. Chemotherapy and the largest diameter of lesion in CT scanning image were independent prognostic factors for those patients.